private async Task InitConnection(Socket socket)
{
try
{
const int loginMagic = 10;
const int reconnectMagic = 18;
const int normalConnectMagic = 16;
const int crcCount = 9;
const int initMagicZeroCount = 8;
const int initHandshakeMagic = 14;
const int keyCount = 4;
const int randomKeySize = sizeof(long);
_log.Debug(this, "Initializing socket");
var blob = new Blob(256);
// initial handshake
await SocketReceive(socket, blob, 2);
var magic = blob.ReadByte();
if (magic != initHandshakeMagic)
{
_log.Debug(this, $"Killing socket due to back handshake magic ({magic})");
socket.Dispose();
return;
}
// another byte contains a bit of the username but we dont care about that
blob.ReadCaret++;
for (var i = 0; i < initMagicZeroCount; i++)
{
blob.Write(0);
}
var sState = _server.GetState();
if (sState.HasFlag(ServerStateFlags.PlayersFull))
{
await KillBadConnection(socket, blob, InitResponseCode.WorldIsFull);
return;
}
if (sState.HasFlag(ServerStateFlags.LoginDisabled))
{
await KillBadConnection(socket, blob, InitResponseCode.LoginServerOffline);
return;
}
// initMagicZeroCount can be any InitResponseCode
blob.Write((byte)InitResponseCode.ContinueToCredentials);
// write server isaac key
var serverKey = new byte[randomKeySize];
_rng.NextBytes(serverKey);
blob.WriteBlock(serverKey, 0, randomKeySize);
// send the packet
await SocketSend(socket, blob);
// receive login block
// header
await SocketReceive(socket, blob, blob.Buffer.Length);
// todo : catch crypto exceptions
var decrypted = _crypto.ProcessBlock(blob.Buffer, 0, blob.Buffer.Length);
blob.Overwrite(decrypted, 0, 0);
// verify login header magic
magic = blob.ReadByte();
if (magic != normalConnectMagic && magic != reconnectMagic)
{
await KillBadConnection(socket, blob, InitResponseCode.GeneralFailure,
$"Invalid login block magic: {magic}");
return;
}
var isReconnecting = magic == reconnectMagic;
//1 - length
//2 - 255
// skip 'em
blob.ReadCaret += 2;
// verify revision
var revision = blob.ReadInt16();
if (revision != _revision)
{
await KillBadConnection(socket, blob, InitResponseCode.MustUpdate);
return;
}
var isLowMem = blob.ReadByte() == 1;
// read crcs
var crcs = new int[crcCount];
for (var i = 0; i < crcCount; i++)
{
crcs[i] = blob.ReadInt32();
}
// login block
// check login magic
magic = blob.ReadByte();
if (magic != loginMagic)
{
await KillBadConnection(socket, blob, InitResponseCode.GeneralFailure,
$"Invalid login magic: {magic}");
return;
}
// read client&server keys
var keys = new int[keyCount];
for (var i = 0; i < keyCount; i++)
{
keys[i] = blob.ReadInt32();
}
var signlinkUid = blob.ReadInt32();
// try read user/pass
string username;
string password;
if (!blob.TryReadString(out username, PlayerComponent.MaxUsernameChars))
{
await KillBadConnection(socket, blob, InitResponseCode.GeneralFailure,
"Overflow detected when reading username.");
return;
}
if (!blob.TryReadString(out password, PlayerComponent.MaxPasswordChars))
{
await KillBadConnection(socket, blob, InitResponseCode.GeneralFailure,
"Overflow detected when reading password.");
return;
}
username = username.ToLowerInvariant();
// check if user is logged in
var loggedInPlayer = _players.Get(username);
if (isReconnecting)
{
// check if valid user
if (loggedInPlayer == null)
{
await KillBadConnection(socket, blob, InitResponseCode.GeneralFailure,
"Tried to reconnect to player that is not present in ent pool.");
return;
}
var net = loggedInPlayer.Get().GetNetwork();
var player = loggedInPlayer.Get().AssertGetPlayer();
if (net == null)
{
await KillBadConnection(socket, blob, InitResponseCode.GeneralFailure,
"Reconnect player target exists with no network component.");
return;
}
// check if we can reconnect
if (!net.CanReinitialize(signlinkUid))
{
await KillBadConnection(socket, blob, InitResponseCode.GeneralFailure,
"Tried to reconnect but player is not available for reconnecting.");
return;
}
// check if the password matches
if (!_db.IsValidPassword(player.Username, password))
{
await KillBadConnection(socket, blob, InitResponseCode.InvalidCredentials);
return;
}
// all's good, queue reconnect.
blob.Write((byte)InitResponseCode.ReconnectDone);
_loginQueue.Enqueue(new ReconnectPlayerLogin(loggedInPlayer, socket, signlinkUid));
}
else
{
if (loggedInPlayer != null)
{
await KillBadConnection(socket, blob, InitResponseCode.AccountAlreadyLoggedIn);
return;
}
SerializablePlayerModel model = null;
// figure out whether we need to serialize the acc or make anew one.
if (_db.PlayerExists(username))
{
// check pw
if (!_db.IsValidPassword(username, password))
{
await KillBadConnection(socket, blob, InitResponseCode.InvalidCredentials);
return;
}
model = _db.Load(username);
if (model == null)
{
_log.Warning(this, $"Failed loading player for {username}");
await KillBadConnection(socket, blob, InitResponseCode.GeneralFailure);
return;
}
}
else
{
model = SerializablePlayerModel.Default(username, _skills);
_db.SetPassword(username, password);
}
blob.Write((byte)InitResponseCode.LoginDone);
blob.Write(0); // is flagged
blob.Write((byte)model.TitleId);
var login = new NormalPlayerLogin(
_services,
_greeting,
model,
socket,
signlinkUid);
_loginQueue.Enqueue(login);
}
await SocketSend(socket, blob);
socket.Blocking = false;
_log.Debug(this, "Done socket init.");
}
catch (SocketException)
{
_log.Debug(this, "SocketException in Entry.");
}
catch (ObjectDisposedException)
{
_log.Debug(this, "ObjectDisposedException in Entry.");
}
catch (CryptoException cryptEx)
{
_log.Exception(this, "Crypto Exception in EntryPoint.", cryptEx);
}
catch (Exception ex)
{
_log.Exception(this, "Unhandled exception in EntryPoint.", ex);
Debug.Fail(ex.ToString());
}
}